This invention relates to conveyors of the type in which the conveyance path is cooperatively defined by and between confronting portions of two endless gripper chain assemblies and in which the two endless gripper chain assemblies operate in opposite senses such that their confronting portions are effective to grip and move articles along the conveyance path. More specifically the present invention relates to an improvement in the drive for this type of conveyor.
Such conveyors are useful in gripping articles of various shapes, such as are common in the bottling, container, and automotive industries. Many of these articles have circular shapes, but such a shape is not essential for usage of this type of conveyor. Conveyors can be constructed in various sizes and configurations; the gripper chain assemblies themselves can fully support the conveyed articles such that no additional means of support is required along the conveyance path.
These conveyors can also be made quite versatile. For example, the direction of conveyance can be reversed simply by reversing the senses in which the two gripper chain assemblies operate.
The particular form for the conveyor which is to be described herein is an elevator-lowerator which is effective to elevate articles when operated in one direction and to lower articles when operated in the opposite direction.
A further example of versatility comprises endowing the conveyor with a means for adjusting the two gripper chain assemblies toward and away from each other so that their confronting portions can be set to a particular distance apart for a particular size of articles to be conveyed. In other words, such a conveyor is capable of conveying different sized articles by simply readjusting the positions of the two endless gripper chain assemblies in relation to each other. In some conveyors it is even possible to make adjustments in the track of the conveyance path.
Drives for double gripper chain conveyors have heretofore comprised either an independent prime mover for each endless gripper chain assembly, or a single prime mover which is coupled to the two endless gripper chain assemblies by a complicated mechanism consisting of various shafts, couplings, universal joints, and sprockets for reversing rotation.
In the case of a drive which utilizes two independent prime movers, measures are often taken to insure that they are synchronized so that the two confronting portions of the gripper chain assemblies travel in unison as they grip and convey articles. Sometimes special synchronizing means are required to achieve this result.
The other type of drive which comprises shafts, couplings, and universal joints is a complicated mechanism requiring a number of individual parts which have to be assembled together.
The present invention is directed to an improvement in the drive for this type of a conveyor, and it possesses significant advantages over the prior drives which were just described.
The invention is especially for a conveyor in which the two gripper chain assemblies are relatively adjustable. The invention eliminates the use of two independent prime movers and the synchronizing means characteristic of the one prior drive, and in the case of the other prior design, the invention eliminates the drive box which comprises the complicated system of shafts, couplings, sprockets, and universal joints.
In a conveyor in which the gripper chain assemblies are adjustable, the invention enables the drive to be adjusted concurrently with the adjustment of the two gripper chain assemblies with at most a loosening of fasteners, a repositioning of the drive, and a retightening of the fasteners. Indeed, in one particular embodiment of the invention the drive automatically tracks the adjustment of the gripper chain assemblies so that there is not even the need to loosen and retighten any fasteners at all.
The invention affords a number of significant advantages over the prior art, and a particularly significant one is the fact that it eliminates the complicated constructions of prior drives. The present invention yields a very significant saving in the cost of the drive which is reflected in a similar saving in the total cost of the conveyor. Moreover, because it eliminates the complexities of the prior drives, the invention is less prone to operating problems, and if maintenance or repair is needed, the present invention enables same to be more conveniently and economically performed.
Briefly, the preferred embodiment of the invention comprises an electric motor operating through a reducer to drive the two gripper chain assemblies. The reducer is coupled with the respective gripper chain assemblies by sheaves and drive belts. The drive is mounted on a base plate which is itself adjustably positionable on the conveyor's frame so that when the gripper chain assemblies are adjusted on the frame, there can be a similar adjustment of the drive base plate on the frame but without the need to make any other changes in the drive. At most, all that may be required is an unloosening of fasteners which fasten the base plate to the frame to enable the adjustment to be performed, and then a retightening of those fasteners after the desired adjustment has been obtained. In another embodiment there is not even any need to loosen and retighten fasteners because in this other embodiment, the base plate automatically tracks the adjustment of the gripper chain assemblies whenever the gripper chain assembly adjustment is performed.
The foregoing features, advantages and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.